Switch



`OCL 14, 1947. v 1, A RUGH' 2,429,074

SWITCH Filed Nov. 12, 1946 .j jf 5J' .fz 5a/5g j" Z da I jY 3 N v t@ I lif F595 veuf/Erf U Patented Oct. 14, 1947 UNITED STATES PATENT GFI-ICESWITCH James A. Rngh. Chicago, lll. Application November 12, 1946,Serial No. 709,278

3 Claims. (Cl. 20D-67) The present invention relates to an electricalswitch that has an on and oil position, each of which positions can bepositively held.

More specifically the invention has to do with that type of snap-actingswitch commonly known in the electrical trade as a 'microswitch whereinonly very short movements of an arm are required to move an electricalcontact member between the on and ofl'" positions of the switch. Theusual microswitch, however, is a snap-acting type of switch that isspring biased in either the "on or off position and requires constantpressure against the movable contact member to hold -the member in theother position.

The switch forming the subject matter of the present invention differsfrom the conventional microswitch in that provisions are made forpositively holding the contact member in both the "on and the ofipositions.

The primary advantage of the present invention is that all oi theadvantages of a conventional microswitch are embodied in a switch thatis v adapted to hold both the on and the "off positions. Very littleforce is needed to actuate the switch and the distance of travel of themember that actuates the switch is very short as is characteristic ofthe conventional microswitch.

'I'he foregoing constitute some of the objects and advantages of thepresent invention, others of which will become apparent from thefollowing description and the drawings, in which Fig. 1 is alongitudinal sectional view through the switch and the housingsurrounding same, the view being taken on the line I-I of Fig. 2:

Fig. 2 is an elevational view of the switch shown in Fig. 1 with thehousing removed, the view being taken in the direction of the arrows 2-2of Fig. 1;

Fig. 3 is a transverse sectional view through a portion of the switch,the view being taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional view corresponding to Fig. 1, butillustrating the switch parts disposed in the closed circuit positionrather than in the open circuit position; and

Fig. 5 is an enlarged fragmentary perspective view of the spring elementemployed in the switch shown in Fig. 1.

For purposes of illustration a single embodiment of the presentinvention has been selected,

it being recognized however that many modifications may be made `withoutdeparting from the intended scope of the invention.

Referring to the drawings the present embodiment of the invention isillustrated in the form of a switch that is mounted in a housinggenerally indicated at I5 that comprises a box I9 having a peripheralange |'I to which is secured a removable coverplate I8.

The switch comprises a frame member I9 that is suitably mounted in thehousing I5. This trame member |9 has at one Aend a projecting portion 20that extends outwardly from one face of the frame member I9 and a secondprojecting portion 2| that extends beyond the opposite face of the framemember. Extending substantially parallel with respect to the framemember I9 is a movable contact member generally indicated at 22 that issecured at one end to the projecting portion 20 of the frame member I9by means oi a bolt 23 that passes through the projecting portions 20 and2|. The bolt 23 is threaded at its opposite end to receive a nut 24. Awasher 25 is disposed between the head of the bolt 23 and the contactmember 22. At the opposite side of the frame member I9 is a switchactuating member generally indicated at 28 that is secured at one end tothe projecting portion 2| of the frame member I9 by means of the bolt 23and nut 24. A washer 21 is mounted between the nut 24 and the actuatingmember 28.

Thejcontact member 22 comprises a frame-like contact portion 28 (Fig. 2)that includes lower and upper parallel portions 29 and 30 connected byside portions 3| and 32. A central portion 33 is integral with thelowerportion 29 and extends' toward the opposite end portion 20 butterminates short of the end portion 30 as at 34. This central portion 33has a width less than the distance between the side portions 3| and 32as best indicated in Fig. 2. Adjacent to the free end 34 of the centralportion 33 is a notch 35. An arcuate spring 36 (Fig. 1) is provided withan ear 31 at its lower edge, which ear is adapted to project into anotch 35 in the central portion 33. As best shown in Fig. 5 the endportion 30 of the contact member 28 is provided with a notch 38 that isadapted to receive an ear 39 on the corresponding end of the arcuatespring 36 to hold the upper end of the spring in place.

The actuating member 26 (Fig. 1) comprises a leaf spring 40 that hasattached to its free end an arm 4| that is pivoted at 42. This arm 4|projects through an aperture 43 in the frame member I9 and in the formshown is provided with a relatively wide spring engaging edge 44including a pair of engaging notches 45 and 46. As best shown in Fig. 4the relatively fine wirelike guide member 41 is fixed at 48 to the side,of ,the arm 4I and the arcuate spring 3E is almacen provided with anaperture B6, through which aperture the guide member 41 projects. Thiswire-like guide member 41 though fixed at 48 to the arm 4I is adapted toex though it has the characteristics oi a spring that constantly tendsto maintain its normal position substantially along the central axis ofthe arm 4 i The free end of the contact portion 28 of the contactmember' 22 is provided with a contact engaging surface 5D that isadapted to engage a cooperating surface 5I (Fig. 1) on the end of anelectrical conductor 52. This conductor 52 is secured to the frame I9 at58 (Fig. 2) and is normally spaced from the frame member I9 as indicatedin Fig. 1. A stop 54 is provided by the end of a screw 55 that passesthrough the frame member I9 and is adapted to limit the movement in onedirection of the contact portion 28 of the contact member 22.

Projecting through the cover plate I6 is a switch button 56 that isprovided on its inner end with a boss 51 that engages the leaf spring lof the actuating member 26. An annular shoulder portion 58 is providedbetween the boss 51 and the enlarged portion of the actuating button 56and is adapted to engage the inner face of the cover plate I8 as bestshown in Fig. l.. In operating the switch pressure is applied onto theactuating button 56 so as to move this button to the left (Fig. l). Thismovement of the button 56 rotates the leaf spring 4@ in the direction ofthe arrow A so as to move the arm di to the left until the notch 45 inthe engaging surface 44 engages the adjacent end of the arcuate spring36. Upon further movement of the button 56 to the left force istransmitted through the arm it so as to force the adjacent edge oi thearcuate spring 36 in the direction indicated by the arrow B causing thespring 36 to rotate and carry with it the contact portion 28 of thecontact member 22 so that this contact portion 2t moves from itsposition shown in Fig. 1 in a direction toward the contacting surface iDuring this movement the rotation of the arcuate spring 36 in acounterclockwise direction moves the central portion 33 of the contactmember 22 in a clockwise direction so as to bring the central portion 33and the contact portion 28 into the same plane. This relam tive movementas between the central portion 33 of the contact portion 28 of thecontact member 22 shortens the distance between the notches 35 (Fig. 2)and the nearest edge of the end portion 3U thereby compressing thearcuate spring 36. This relative position between the central portion 33and the contact portion 26 oi. the contact member 22 corresponds with adeadcenter position so that upon further movement of the arm 4l to theleft with the resulting counterclockwise movement of the arcuate spring36 the central portion 33 of the contact member 22 passes thedead-center position with respect to the contact portion 28 and theforce of compression in the arcuate spring 36 is released so as to snapthe contact portion 28 of the contact member 22 to its extreme leftposition shown in Fig. 4 with the contact surface 50 against the face ofthe cooperating engaging member 5i. In this position shown in Fig. 4 anelectrical circuit through the switch is completed, the circuitcomprising the cooperating surfaces 50 and 5I, the contact portion 28 ofthe contact member 22 and lead wires (not shown) that would normally beelectrically connected to the bolt 23 and screw 53 While the arm Il ismoving in the direction cf the arrow A in Fig. l the arm is preventedfrom rotating about the pivot point l2 on the free end of the leafspring 40 by the cooperation between the notch 45 in the engaging edgel44 and the adjacent end of the arcuate spring 36. During this samemovement the arcuate spring 36 is caused to rotate in a counterclockwisedirection as previously described so that the guide member 41 isdistorted or bent downwardly out o! its normally relative position withrespect tothe arm 4i. As soon as the 'dead-center position o! thecentral portion 33 of the contact member 22 is passed through thearcuate spring 38 is caused to rotate rapidly to the position shown inFig. 4 so that the upper edge 39 of the arcuate spring 36 moves out ofengagement with theslot 45 in the arm 4l at which time the guide springIl is allowed to return to its normal straight position so as to movethe arm 4i about the pivot point 42 to the lower position shown in Fig.4. Slot 46 is now aligned with the lower edge 31 of the arcuate spring36. When the actuating button 56 is allowed to return to the position`shown in Fig. l the circuit through the switch is now maintainedclosed. To open the circuit through the switch pressure is again appliedto the actuating button 56 so as to move the leai spring in thedirection of the arrow A, but in this instance the lower edge 31 of thearcuate spring 36 is engaged in the notch 46 so that the arcuate springis now rotated in a clockwise direction, thereby returning the centralportion of the contact member 22 to the dead-center position withrespect to the contact portion 26 and upon further movement of thebutton 5t this dead-center position is passed so that the arcuate springtt forces the contact portion 2t rapidly,r away from the engagingsurface 5i to the position shown in Fig. l, thereby snapping the switchto its open position. Force on the actuating button 56 is then releasedand the parts returned to their relative position shown in Fig. l withthe arm il in its uppermost position where the notch l5 is aligned withthe upper edge 39 oi the arcuate spring Thus there is disclosed aneiective on and off switch that is adapted to hold either position.

E claim:

l. A switch of the class described comprising a circuit contactingmember and a cooperating member, each having a free end, the free endsbeing spaced apart, an arcuate shaped spring interposed between the freeends and having portions pivotally secured to the members adjacent totheir free ends, an actuating member including a pivoted arm adapted toactuate alternatively the contacting member and the cooperating memberadjacent to said free ends, and a guide spring normally centering thearm relative to the arcuate spring.

2. A switch of the class described comprising a circuit contactingmember and a cooperating member, each having a free end, the free endsbeing spaced apart, an arcuate shaped spring interposed between the freeends and having portions pivotally secured to the members adjacent totheir free ends, an actuating member including a pivoted arm adapted toactuate alternatively the contacting member and the cooperating memberadjacent to said free ends, and a guide spring normally centering thearm relative to the arcuate spring, the contacting member andcooperating member being adapted tov pivot with respect to each otherand to assume ment of said cooperating member, and means on thecontacting member loosely interconnected ing smooth portions restingupon the said supv ports. and said supports being in suiiiciently closeproximity to each other to hold said spring under compression withportions thereof in the form of an arm, means for maintaining saidspring in operative association with said members and for rocking itupon its support, said means including means on the cooperating memberloosely interconnected with a portion of the spring so as to engage saidspring and move it bodily upon said supports with a rocking actionduring movewith another portion of said spring which permits a rockingmovement of said spring upon the support of the cooperating member, anactuating member including a pivoted arm adapted to actuatealternatively the contacting member and the cooperating member adjacentto said free ends, and a guide spring normally centering the armrelative to the arcuate spring.

- JAMES A. RUGH.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number l Name Date 1,910,510 Warner May 23, 1933zo 2,295,151 Baak Sept. 8, 1942 2,237,705 Kohl Apr. 8, 1941

